I need to write data to a physical address between 0xD0000 and 0xDFFFF
I have download the windows DDK but have no experience with this and
would like to get up and running very quickly can any one point me in
the direction of an example that I could modify. I found a reference
to an example program called GENPORT but can't seem to find any similar
example in the latest DDK. I have also found an already written and
complied driver called portTalk but this only allows you to talk to an
addresses between 0x0000 and 0xFFFF. Any help most appreicated.
Thanks,
Grant 6 6347
Grant wrote:
I need to write data to a physical address between 0xD0000 and 0xDFFFF
I have download the windows DDK but have no experience with this and
would like to get up and running very quickly can any one point me in
the direction of an example that I could modify. I found a reference
to an example program called GENPORT but can't seem to find any
similar example in the latest DDK. I have also found an already
written and complied driver called portTalk but this only allows you
to talk to an addresses between 0x0000 and 0xFFFF. Any help most
appreicated.
C++ _language_ does not define "DDK" or "windows". Try looking in
the 'microsoft.publ ic.*' newsgroup hierarchy.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
Grant posted:
I need to write data to a physical address between 0xD0000 and 0xDFFFF
int main()
{
char unsigned *const min = (char unsigned*)0xD00 00;
char unsigned const *const max = (char unsigned*)0xDFF FF;
char unsigned *p = min;
do *p++ = 5;
while (max != p);
*p = 5;
}
--
Frederick Gotham
Frederick Gotham wrote:
Grant posted:
>I need to write data to a physical address between 0xD0000 and 0xDFFFF
int main()
{
char unsigned *const min = (char unsigned*)0xD00 00;
char unsigned const *const max = (char unsigned*)0xDFF FF;
char unsigned *p = min;
do *p++ = 5;
while (max != p);
*p = 5;
}
The code above does not guarantee to access *physical addresses*,
only *virtual* ones. Besides, there is no guarantee such virtual
addresses exist.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
Victor Bazarov wrote:
Frederick Gotham wrote:
Grant posted:
I need to write data to a physical address between 0xD0000 and
0xDFFFF
int main()
{
char unsigned *const min = (char unsigned*)0xD00 00;
char unsigned const *const max = (char unsigned*)0xDFF FF;
char unsigned *p = min;
do *p++ = 5;
while (max != p);
*p = 5;
}
The code above does not guarantee to access *physical addresses*,
only *virtual* ones. Besides, there is no guarantee such virtual
addresses exist.
isn't casting an int to a pointer implemetation defined behaviour? And
isn't dereferencing the resulting pointer undefined behaviour?
--
Nick Keighley
Thanks I'll do that
Victor Bazarov wrote:
Grant wrote:
I need to write data to a physical address between 0xD0000 and 0xDFFFF
I have download the windows DDK but have no experience with this and
would like to get up and running very quickly can any one point me in
the direction of an example that I could modify. I found a reference
to an example program called GENPORT but can't seem to find any
similar example in the latest DDK. I have also found an already
written and complied driver called portTalk but this only allows you
to talk to an addresses between 0x0000 and 0xFFFF. Any help most
appreicated.
C++ _language_ does not define "DDK" or "windows". Try looking in
the 'microsoft.publ ic.*' newsgroup hierarchy.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
Nick Keighley wrote:
Victor Bazarov wrote:
>Frederick Gotham wrote:
>>Grant posted:
>>>I need to write data to a physical address between 0xD0000 and 0xDFFFF
int main() { char unsigned *const min = (char unsigned*)0xD00 00; char unsigned const *const max = (char unsigned*)0xDFF FF;
char unsigned *p = min;
do *p++ = 5; while (max != p);
*p = 5; }
The code above does not guarantee to access *physical addresses*, only *virtual* ones. Besides, there is no guarantee such virtual addresses exist.
isn't casting an int to a pointer implemetation defined behaviour? And
isn't dereferencing the resulting pointer undefined behaviour?
Any undefined behaviour can still be defined by the implementation,
the Standard does not prohibit that. FWIW in MS-DOS ("real mode" of
x86 processors), for instance, the mechanism Frederick showed *is*
the way to access a particular location in physical memory. There
are, I am sure, other platforms that implement it that way. The only
reason it's so is that the mapping between virtual space and physical
space is 1-to-1 there.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
by: Mark |
last post by:
Thanks.
|
by: lupher cypher |
last post by:
Hi,
I'm trying to access memory directly at 0xb800 (text screen). I tried this:
char far* screen = (char far*)0xb8000000;
but apparently c++ compiler doesn't know "far" (says "syntax error
before *"). I've tried using __far, _far, FAR, _FAR, and __FAR, all with
the same result. So, then I tried this:
|
by: Olumide |
last post by:
Thats the question.
I know about virtual memory, and the MMU. I just wonder if array members
guaranteed to be contiguous in physical memory (and if so, why).
Thanks,
Olumide
|
by: Ronald de Feijter |
last post by:
In a mechatronic system I can control some motors and
servos by setting values between 0 and 255 at specific
memory addresses. My problem is how to access these memory
addresses within C#. I know I can access memory locations
by using pointers in unsafe code. But I only know how to
assign a pointer to the address of a declared variable (by
using the & operator), not to a specific address.
Does anybody have a suggestion?
|
by: Sharon |
last post by:
I have an application that fails to allocate all its memory on physical memory.
I have a Windows XP with 2 GByte RAM.
Can anybody tell me how to configure the allowed physical memory for each
application in the Windows XP so the application memory allocation will not
use any of the virtual memory?
I’m not talking about the .NET framework. I need to configure the Windows
itself.
| |
by: nkrisraj |
last post by:
Hi,
I have a following structure:
typedef struct
{
RateData rdr;
int RateID;
char RateBalance;
} RateInfo;
|
by: sethukr |
last post by:
hi,
i need to store a value to a particular memory location without having
a variable.
So, how can i access a 'memory address' without using variables??
Is it possible in C???
Plz, help me..
|
by: john |
last post by:
I would like to view physical memory that is mapped to a pci board. I
am using a tool called WinIO to try to create a virtual address to
that physical memory. It works for both read and write of some
addresses, like 0x9FFF0. However, the resource the board uses is
address at 0xE8100000 which I cannot pick up with the tool. I have
confirmed that address in windows device manager and in the BAR0 entry
in the table that the PCI board...
|
by: Sharaola |
last post by:
Direct question , please direct answer
Want to access physical memory as 0x80 in my code
like
namespace ff
{
class Program
{
|
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
|
by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
| |
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
|
by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own....
Now, this would greatly impact the work of software developers. The idea...
|
by: isladogs |
last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM).
In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules.
He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms.
Adolph will...
|
by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
|
by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
|
by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
| |
by: bsmnconsultancy |
last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...
| |